MASSR

MASSR may refer to:

The Mari Autonomous Soviet Socialist Republic, an autonomous polity of the Russian SFSR The Mordovian Autonomous Soviet Socialist Republic, an autonomous polity of the Russian SFSR The Moldavian Autonomous Soviet Socialist Republic, an autonomous polity of the Ukrainian SSR The mass-asymptotic speed relation, a relation between the mass and rotation speed of a disk galaxy, as predicted by Modified Newtonian dynamics